This invention relates to a vehicle body positioning apparatus and, more specifically, to apparatus for locating a vehicle body in a predetermined position at a work station in a automobile manufacturing assembly line.
In those instances where vehicle bodies are conveyed by a hanger, one might consider the use of an arrangement where the hanger is stopped at a predetermined location and the vehicle body is lifted from the hanger and set in position by a lifting device having means for positioning the vehicle body.
With such an arrangement, however, it often happens that the desired predetermined accurate position of the vehicle body cannot be provided by the lifting device because the vehicle body is not properly positioned on the conveying hanger and/or the conveying hanger is not stopped precisely at the desired stop position of the hanger.
There is also known, as disclosed in Japanese Unexamined Patent Application Publication No. Sho 61 (1986) - 21873, a type of apparatus that is useful in detecting by means of a visual sensor the extent of error in the improper position of a vehicle body at a work station and compensation for such error is made by means of a position compensation control provided on the automatic machine at that work station. However, this apparatus is complicated and expensive. It is therefore desirable to have some means by which it is possible to accurately set a vehicle body in the desired predetermined position and thereby eliminate the need for a position error detector and position compensation control of the automatic machine at that particular work station.
The present invention avoids the foregoing problems and difficulties by providing an apparatus which prevents an error in positioning a vehicle body on a hanger and also Position errors resulting from the hanger being stopped at the wrong or inprecise position relative to a work station.